/**
 * Copyright (c) 2007, AurorisNET.
 *
 * Everyone is permitted to copy and distribute verbatim copies of this license
 * document, but changing it is not allowed.
 *
 * Preamble
 *
 * This license establishes the terms under which a given free software Package
 * may be copied, modified, distributed, and/or redistributed. The intent is
 * that the Copyright Holder maintains some artistic control over the
 * development of that Package while still keeping the Package available as open
 * source and free software.
 *
 * You are always permitted to make arrangements wholly outside of this license
 * directly with the Copyright Holder of a given Package. If the terms of this
 * license do not permit the full use that you propose to make of the Package,
 * you should contact the Copyright Holder and seek a different licensing
 * arrangement.
 *
 * Definitions
 *
 * "Copyright Holder" means the individual(s) or organization(s) named in the
 * copyright notice for the entire Package.
 *
 * "Contributor" means any party that has contributed code or other material to
 * the Package, in accordance with the Copyright Holder's procedures.
 *
 * "You" and "your" means any person who would like to copy, distribute, or
 * modify the Package.
 *
 * "Package" means the collection of files distributed by the Copyright Holder,
 * and derivatives of that collection and/or of those files. A given Package may
 * consist of either the Standard Version, or a Modified Version.
 *
 * "Distribute" means providing a copy of the Package or making it accessible to
 * anyone else, or in the case of a company or organization, to others outside
 * of your company or organization.
 *
 * "Distributor Fee" means any fee that you charge for Distributing this Package
 * or providing support for this Package to another party. It does not mean
 * licensing fees.
 *
 * "Standard Version" refers to the Package if it has not been modified, or has
 * been modified only in ways explicitly requested by the Copyright Holder.
 *
 * "Modified Version" means the Package, if it has been changed, and such
 * changes were not explicitly requested by the Copyright Holder.
 *
 * "Original License" means this Artistic License as Distributed with the
 * Standard Version of the Package, in its current version or as it may be
 * modified by The Perl Foundation in the future.
 *
 * "Source" form means the source code, documentation source, and configuration
 * files for the Package.
 *
 * "Compiled" form means the compiled bytecode, object code, binary, or any
 * other form resulting from mechanical transformation or translation of the
 * Source form.
 *
 * Permission for Use and Modification Without Distribution
 *
 * (1) You are permitted to use the Standard Version and create and use Modified
 * Versions for any purpose without restriction, provided that you do not
 * Distribute the Modified Version.
 *
 * Permissions for Redistribution of the Standard Version
 *
 * (2) You may Distribute verbatim copies of the Source form of the Standard
 * Version of this Package in any medium without restriction, either gratis or
 * for a Distributor Fee, provided that you duplicate all of the original
 * copyright notices and associated disclaimers. At your discretion, such
 * verbatim copies may or may not include a Compiled form of the Package.
 *
 * (3) You may apply any bug fixes, portability changes, and other modifications
 * made available from the Copyright Holder. The resulting Package will still be
 * considered the Standard Version, and as such will be subject to the Original
 * License.
 *
 * Distribution of Modified Versions of the Package as Source
 *
 * (4) You may Distribute your Modified Version as Source (either gratis or for
 * a Distributor Fee, and with or without a Compiled form of the Modified
 * Version) provided that you clearly document how it differs from the Standard
 * Version, including, but not limited to, documenting any non-standard
 * features, executables, or modules, and provided that you do at least ONE of
 * the following:
 *
 *      (a) make the Modified Version available to the Copyright Holder of the
 *          Standard Version, under the Original License, so that the Copyright
 *          Holder may include your modifications in the Standard Version.
 *
 *      (b) ensure that installation of your Modified Version does not prevent
 *          the user installing or running the Standard Version. In addition,
 *          the Modified Version must bear a name that is different from the
 *          name of the Standard Version.
 *
 *      (c) allow anyone who receives a copy of the Modified Version to make the
 *          Source form of the Modified Version available to others under
 *
 *          (i) the Original License or
 *
 *          (ii) a license that permits the licensee to freely copy, modify and
 *              redistribute the Modified Version using the same licensing terms
 *              that apply to the copy that the licensee received, and requires
 *              that the Source form ofthe Modified Version, and of any works
 *              derived from it, be made freely available in that license fees
 *              are prohibited but Distributor Fees are allowed.
 *
 * Distribution of Compiled Forms of the Standard Version or Modified Versions
 * without the Source
 *
 * (5) You may Distribute Compiled forms of the Standard Version without the
 * Source, provided that you include complete instructions on how to get the
 * Source of the Standard Version. Such instructions must be valid at the time
 * of your distribution. If these instructions, at any time while you are
 * carrying out such distribution, become invalid, you must provide new
 * instructions on demand or cease further distribution. If you provide valid
 * instructions or cease distribution within thirty days after you become aware
 * that the instructions are invalid, then you do not forfeit any of your rights
 * under this license.
 *
 * (6) You may Distribute a Modified Version in Compiled form without the
 * Source, provided that you comply with Section 4 with respect to the Source of
 * the Modified Version.
 *
 * Aggregating or Linking the Package
 *
 * (7) You may aggregate the Package (either the Standard Version or Modified
 * Version) with other packages and Distribute the resulting aggregation
 * provided that you do not charge a licensing fee for the Package. Distributor
 * Fees are permitted, and licensing fees for other components in the
 * aggregation are permitted. The terms of this license apply to the use and
 * Distribution of the Standard or Modified Versions as included in the
 * aggregation.
 *
 * (8) You are permitted to link Modified and Standard Versions with other
 * works, to embed the Package in a larger work of your own, or to build
 * stand-alone binary or bytecode versions of applications that include the
 * Package, and Distribute the result without restriction, provided the result
 * does not expose a direct interface to the Package.
 *
 * Items That are Not Considered Part of a Modified Version
 *
 * (9) Works (including, but not limited to, modules and scripts) that merely
 * extend or make use of the Package, do not, by themselves, cause the Package
 * to be a Modified Version. In addition, such works are not considered parts of
 * the Package itself, and are not subject to the terms of this license.
 *
 * General Provisions
 *
 * (10) Any use, modification, and distribution of the Standard or Modified
 * Versions is governed by this Artistic License. By using, modifying or
 * distributing the Package, you accept this license. Do not use, modify, or
 * distribute the Package, if you do not accept this license.
 *
 * (11) If your Modified Version has been derived from a Modified Version made
 * by someone other than you, you are nevertheless required to ensure that your
 * Modified Version complies with the requirements of this license.
 *
 * (12) This license does not grant you the right to use any trademark, service
 * mark, tradename, or logo of the Copyright Holder.
 *
 * (13) This license includes the non-exclusive, worldwide, free-of-charge
 * patent license to make, have made, use, offer to sell, sell, import and
 * otherwise transfer the Package with respect to any patent claims licensable
 * by the Copyright Holder that are necessarily infringed by the Package. If you
 * institute patent litigation (including a cross-claim or counterclaim) against
 * any party alleging that the Package constitutes direct or contributory patent
 * infringement, then this Artistic License to you shall terminate on the date
 * that such litigation is filed.
 *
 * (14) Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER
 * AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW.
 * UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY
 * OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.pentaho.gwt.widgets.client.colorpicker;

/**
 * Copyright (c) 2007, AurorisNET.
 * 
 * Everyone is permitted to copy and distribute verbatim copies of this license 
 * document, but changing it is not allowed.
 * 
 * Preamble
 * 
 * This license establishes the terms under which a given free software Package 
 * may be copied, modified, distributed, and/or redistributed. The intent is 
 * that the Copyright Holder maintains some artistic control over the 
 * development of that Package while still keeping the Package available as open
 * source and free software.
 * 
 * You are always permitted to make arrangements wholly outside of this license 
 * directly with the Copyright Holder of a given Package. If the terms of this 
 * license do not permit the full use that you propose to make of the Package, 
 * you should contact the Copyright Holder and seek a different licensing 
 * arrangement.
 * 
 * Definitions
 * 
 * "Copyright Holder" means the individual(s) or organization(s) named in the 
 * copyright notice for the entire Package.
 * 
 * "Contributor" means any party that has contributed code or other material to 
 * the Package, in accordance with the Copyright Holder's procedures.
 * 
 * "You" and "your" means any person who would like to copy, distribute, or 
 * modify the Package.
 * 
 * "Package" means the collection of files distributed by the Copyright Holder, 
 * and derivatives of that collection and/or of those files. A given Package may
 * consist of either the Standard Version, or a Modified Version.
 * 
 * "Distribute" means providing a copy of the Package or making it accessible to
 * anyone else, or in the case of a company or organization, to others outside 
 * of your company or organization.
 * 
 * "Distributor Fee" means any fee that you charge for Distributing this Package
 * or providing support for this Package to another party. It does not mean 
 * licensing fees.
 * 
 * "Standard Version" refers to the Package if it has not been modified, or has
 * been modified only in ways explicitly requested by the Copyright Holder.
 * 
 * "Modified Version" means the Package, if it has been changed, and such 
 * changes were not explicitly requested by the Copyright Holder.
 * 
 * "Original License" means this Artistic License as Distributed with the 
 * Standard Version of the Package, in its current version or as it may be 
 * modified by The Perl Foundation in the future.
 * 
 * "Source" form means the source code, documentation source, and configuration 
 * files for the Package.
 * 
 * "Compiled" form means the compiled bytecode, object code, binary, or any 
 * other form resulting from mechanical transformation or translation of the 
 * Source form.
 * 
 * Permission for Use and Modification Without Distribution
 * 
 * (1) You are permitted to use the Standard Version and create and use Modified
 * Versions for any purpose without restriction, provided that you do not 
 * Distribute the Modified Version.
 * 
 * Permissions for Redistribution of the Standard Version
 * 
 * (2) You may Distribute verbatim copies of the Source form of the Standard 
 * Version of this Package in any medium without restriction, either gratis or 
 * for a Distributor Fee, provided that you duplicate all of the original 
 * copyright notices and associated disclaimers. At your discretion, such 
 * verbatim copies may or may not include a Compiled form of the Package.
 * 
 * (3) You may apply any bug fixes, portability changes, and other modifications
 * made available from the Copyright Holder. The resulting Package will still be
 * considered the Standard Version, and as such will be subject to the Original 
 * License.
 * 
 * Distribution of Modified Versions of the Package as Source
 * 
 * (4) You may Distribute your Modified Version as Source (either gratis or for
 * a Distributor Fee, and with or without a Compiled form of the Modified
 * Version) provided that you clearly document how it differs from the Standard
 * Version, including, but not limited to, documenting any non-standard 
 * features, executables, or modules, and provided that you do at least ONE of 
 * the following:
 * 
 *      (a) make the Modified Version available to the Copyright Holder of the 
 *          Standard Version, under the Original License, so that the Copyright 
 *          Holder may include your modifications in the Standard Version.
 *
 *      (b) ensure that installation of your Modified Version does not prevent 
 *          the user installing or running the Standard Version. In addition, 
 *          the Modified Version must bear a name that is different from the 
 *          name of the Standard Version.
 *
 *      (c) allow anyone who receives a copy of the Modified Version to make the
 *          Source form of the Modified Version available to others under
 *
 *          (i) the Original License or
 *
 *          (ii) a license that permits the licensee to freely copy, modify and 
 *              redistribute the Modified Version using the same licensing terms
 *              that apply to the copy that the licensee received, and requires 
 *              that the Source form ofthe Modified Version, and of any works 
 *              derived from it, be made freely available in that license fees 
 *              are prohibited but Distributor Fees are allowed.
 *
 * Distribution of Compiled Forms of the Standard Version or Modified Versions
 * without the Source
 * 
 * (5) You may Distribute Compiled forms of the Standard Version without the 
 * Source, provided that you include complete instructions on how to get the 
 * Source of the Standard Version. Such instructions must be valid at the time 
 * of your distribution. If these instructions, at any time while you are 
 * carrying out such distribution, become invalid, you must provide new 
 * instructions on demand or cease further distribution. If you provide valid 
 * instructions or cease distribution within thirty days after you become aware 
 * that the instructions are invalid, then you do not forfeit any of your rights
 * under this license.
 *
 * (6) You may Distribute a Modified Version in Compiled form without the 
 * Source, provided that you comply with Section 4 with respect to the Source of
 * the Modified Version.
 *
 * Aggregating or Linking the Package
 *
 * (7) You may aggregate the Package (either the Standard Version or Modified 
 * Version) with other packages and Distribute the resulting aggregation 
 * provided that you do not charge a licensing fee for the Package. Distributor 
 * Fees are permitted, and licensing fees for other components in the 
 * aggregation are permitted. The terms of this license apply to the use and
 * Distribution of the Standard or Modified Versions as included in the
 * aggregation.
 *
 * (8) You are permitted to link Modified and Standard Versions with other 
 * works, to embed the Package in a larger work of your own, or to build 
 * stand-alone binary or bytecode versions of applications that include the 
 * Package, and Distribute the result without restriction, provided the result 
 * does not expose a direct interface to the Package.
 * 
 * Items That are Not Considered Part of a Modified Version
 *
 * (9) Works (including, but not limited to, modules and scripts) that merely 
 * extend or make use of the Package, do not, by themselves, cause the Package 
 * to be a Modified Version. In addition, such works are not considered parts of
 * the Package itself, and are not subject to the terms of this license. 
 * 
 * General Provisions
 *
 * (10) Any use, modification, and distribution of the Standard or Modified
 * Versions is governed by this Artistic License. By using, modifying or 
 * distributing the Package, you accept this license. Do not use, modify, or 
 * distribute the Package, if you do not accept this license.
 *
 * (11) If your Modified Version has been derived from a Modified Version made 
 * by someone other than you, you are nevertheless required to ensure that your 
 * Modified Version complies with the requirements of this license.
 *
 * (12) This license does not grant you the right to use any trademark, service 
 * mark, tradename, or logo of the Copyright Holder.
 *
 * (13) This license includes the non-exclusive, worldwide, free-of-charge 
 * patent license to make, have made, use, offer to sell, sell, import and 
 * otherwise transfer the Package with respect to any patent claims licensable 
 * by the Copyright Holder that are necessarily infringed by the Package. If you
 * institute patent litigation (including a cross-claim or counterclaim) against
 * any party alleging that the Package constitutes direct or contributory patent
 * infringement, then this Artistic License to you shall terminate on the date 
 * that such litigation is filed.
 *
 * (14) Disclaimer of Warranty: THE PACKAGE IS PROVIDED BY THE COPYRIGHT HOLDER 
 * AND CONTRIBUTORS "AS IS' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES. THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR 
 * NON-INFRINGEMENT ARE DISCLAIMED TO THE EXTENT PERMITTED BY YOUR LOCAL LAW. 
 * UNLESS REQUIRED BY LAW, NO COPYRIGHT HOLDER OR CONTRIBUTOR WILL BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY
 * OUT OF THE USE OF THE PACKAGE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 
 * DAMAGE.
 */

/**
 * A helpful class to convert between the HSV and RGB colorspaces.
 * 
 * @author AurorisNET
 */
public class Color {
  private float h; // [0,360] Hue
  private float s; // [0-1] Saturation
  private float v; // [0-1] Value
  private float r; // [0-1] Red
  private float g; // [0-1] Green
  private float b; // [0-1] Blue
  private String hex; // Hexadecimal notation of RGB

  /**
   * Set the Hue, Saturation and Value (Brightness) variables. This will automatically populate the Red, Green, Blue,
   * and Hexadecimal fields, too.
   * 
   * It represents points in the RGB color space, which attempt to describe perceptual color relationships more
   * accurately than RGB. HSV describes colors as points in a cylinder whose central axis ranges from black at the
   * bottom to white at the top with neutral colors between them, where angle around the axis corresponds to hue,
   * distance from the axis corresponds to saturation, and distance along the axis corresponds to lightness, value, or
   * brightness.
   * 
   * @param h
   *          Hue - valid range is 0-359
   * @param s
   *          Saturation - valid range is 0-100
   * @param v
   *          Value (Brightness) - valid range is 0-100
   * @throws java.lang.Exception
   *           A general exception if the Hue, Saturation, or Value variables are out of range.
   */
  public void setHSV( int h, int s, int v ) throws Exception {
    if ( h < 0 || h > 360 ) {
      throw new Exception();
    }
    if ( s < 0 || s > 100 ) {
      throw new Exception();
    }
    if ( v < 0 || v > 100 ) {
      throw new Exception();
    }

    this.h = (float) h;
    this.s = (float) s / 100;
    this.v = (float) v / 100;

    HSVtoRGB( this.h, this.s, this.v );

    setHex();
  }

  /**
   * Sets the Red, Green, and Blue color variables. This will automatically convert to Hue, Saturation and Brightness
   * and Hexadecimal.
   * 
   * The RGB color model is an additive color model in which red, green, and blue light are added together in various
   * ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive
   * primary colors, red, green, and blue.
   * 
   * @param r
   *          Red - valid range is 0-255
   * @param g
   *          Green - valid range is 0-255
   * @param b
   *          Blue - valid range is 0-255
   * @throws java.lang.Exception
   *           Exception if the Red, Green or Blue variables are out of range.
   */
  public void setRGB( int r, int g, int b ) throws Exception {
    if ( r < 0 || r > 255 ) {
      throw new Exception();
    }
    if ( g < 0 || g > 255 ) {
      throw new Exception();
    }
    if ( b < 0 || b > 255 ) {
      throw new Exception();
    }

    this.r = (float) r / 255;
    this.g = (float) g / 255;
    this.b = (float) b / 255;

    RGBtoHSV( this.r, this.g, this.b );

    setHex();
  }

  /**
   * Sets the hexadecimal representation of Red, Green and Blue.
   * 
   * @param hex
   *          The hexadecimal string notation. It must be 6 letters long and consist of the characters 0-9 and A-F.
   * @throws java.lang.Exception
   *           Exception if the hexadecimal string cannot be parsed into its Red, Green, and Blue components.
   */
  public void setHex( String hex ) throws Exception {
    if ( hex.length() == 6 ) {
      setRGB( Integer.parseInt( hex.substring( 0, 2 ), 16 ), Integer.parseInt( hex.substring( 2, 4 ), 16 ), Integer
          .parseInt( hex.substring( 4, 6 ), 16 ) );
    } else {
      throw new Exception();
    }
  }

  /**
   * Converts from RGB to Hexadecimal notation.
   */
  private void setHex() {
    String hRed = Integer.toHexString( getRed() );
    String hGreen = Integer.toHexString( getGreen() );
    String hBlue = Integer.toHexString( getBlue() );

    if ( hRed.length() == 0 ) {
      hRed = "00"; //$NON-NLS-1$
    }
    if ( hRed.length() == 1 ) {
      hRed = "0" + hRed; //$NON-NLS-1$
    }
    if ( hGreen.length() == 0 ) {
      hGreen = "00"; //$NON-NLS-1$
    }
    if ( hGreen.length() == 1 ) {
      hGreen = "0" + hGreen; //$NON-NLS-1$
    }
    if ( hBlue.length() == 0 ) {
      hBlue = "00"; //$NON-NLS-1$
    }
    if ( hBlue.length() == 1 ) {
      hBlue = "0" + hBlue; //$NON-NLS-1$
    }

    this.hex = hRed + hGreen + hBlue;
  }

  /**
   * Returns the integer of the red component of the RGB colorspace, or 0 if it hasn't been set.
   * 
   * @return red component
   */
  public int getRed() {
    return (int) ( r * 255.0f + 0.5f );
  }

  /**
   * Returns the integer of the green component of the RGB colorspace, or 0 if it hasn't been set.
   * 
   * @return green component
   */
  public int getGreen() {
    return (int) ( g * 255.0f + 0.5f );
  }

  /**
   * Returns the integer of the blue component of the RGB colorspace, or 0 if it hasn't been set.
   * 
   * @return blue component
   */
  public int getBlue() {
    return (int) ( b * 255.0f + 0.5f );
  }

  /**
   * Returns the integer of the hue component of the HSV colorspace, or 0 if it hasn't been set.
   * 
   * @return hue component
   */
  public int getHue() {
    return Math.round( h );
  }

  /**
   * Returns the integer of the saturation component of the HSV colorspace, or 0 if it hasn't been set.
   * 
   * @return saturation component
   */
  public int getSaturation() {
    return Math.round( s * 100 );
  }

  /**
   * Returns the integer of the value (brightness) component of the HSV colorspace, or 0 if it hasn't been set.
   * 
   * @return value component
   */
  public int getValue() {
    return Math.round( v * 100 );
  }

  /**
   * Returns the hexadecimal representation of the RGB colorspace.
   * 
   * @return hexadecimal representation
   */
  public String getHex() {
    return hex;
  }

  // r,g,b values are from 0 to 1
  // h = [0,360], s = [0,1], v = [0,1]
  // if s == 0, then h = (undefined)
  /**
   * Converts the RGB colorspace into the HSV colorspace. This private method works exclusively with internal variables
   * and does not return anything.
   * 
   * @param r
   *          Red
   * @param g
   *          Green
   * @param b
   *          Blue
   */
  private void RGBtoHSV( float r, float g, float b ) {
    float min = 0;
    float max = 0;
    float delta = 0;

    min = MIN( r, g, b );
    max = MAX( r, g, b );

    this.v = max; // v

    delta = max - min;

    if ( max != 0 ) {
      this.s = delta / max; // s
    } else {
      // r = g = b = 0 // s = 0, v is undefined
      this.s = 0;
      this.h = 0;
      return;
    }

    if ( delta == 0 ) {
      h = 0;
      return;
    }

    if ( r == max ) {
      this.h = ( g - b ) / delta; // between yellow & magenta
    } else if ( g == max ) {
      this.h = 2 + ( b - r ) / delta; // between cyan & yellow
    } else {
      this.h = 4 + ( r - g ) / delta; // between magenta & cyan
    }

    this.h *= 60; // degrees

    if ( this.h < 0 ) {
      this.h += 360;
    }
  }

  /**
   * Converts the HSV colorspace into the RGB colorspace. This private method works exclusively with internal variables
   * and does not return anything.
   * 
   * @param h
   *          Hue
   * @param s
   *          Saturation
   * @param v
   *          Value (Brightness)
   */
  private void HSVtoRGB( float h, float s, float v ) {
    int i;
    float f;
    float p;
    float q;
    float t;
    if ( s == 0 ) {
      // achromatic (grey)
      this.r = v;
      this.g = v;
      this.b = v;
      return;
    }
    h /= 60; // sector 0 to 5
    i = (int) Math.floor( h );
    f = h - i; // factorial part of h
    p = v * ( 1 - s );
    q = v * ( 1 - s * f );
    t = v * ( 1 - s * ( 1 - f ) );
    switch ( i ) {
      case 0:
        this.r = v;
        this.g = t;
        this.b = p;
        break;
      case 1:
        this.r = q;
        this.g = v;
        this.b = p;
        break;
      case 2:
        this.r = p;
        this.g = v;
        this.b = t;
        break;
      case 3:
        this.r = p;
        this.g = q;
        this.b = v;
        break;
      case 4:
        this.r = t;
        this.g = p;
        this.b = v;
        break;
      default: // case 5:
        this.r = v;
        this.g = p;
        this.b = q;
        break;
    }
  }

  /**
   * A helper function to determine the largest value between the three inputs.
   * 
   * @param a
   *          First value
   * @param b
   *          Second value
   * @param c
   *          Third value
   * @return The value of the largest of the inputs.
   */
  private float MAX( float a, float b, float c ) {
    float max = Integer.MIN_VALUE;
    if ( a > max ) {
      max = a;
    }
    if ( b > max ) {
      max = b;
    }
    if ( c > max ) {
      max = c;
    }
    return max;
  }

  /**
   * A helper function to determine the smallest value between the three inputs.
   * 
   * @param a
   *          First value
   * @param b
   *          Second value
   * @param c
   *          Third value
   * @return The value of the smallest of the inputs.
   */
  private float MIN( float a, float b, float c ) {
    float min = Integer.MAX_VALUE;
    if ( a < min ) {
      min = a;
    }
    if ( b < min ) {
      min = b;
    }
    if ( c < min ) {
      min = c;
    }
    return min;
  }
}
